Low-profile wideband antenna array configured to utilize efficient manufacturing processes

ABSTRACT

A low profile phased array antenna that is configured to be manufactured using additive manufacturing techniques is provided. In one or more embodiments, the phased array can include a plurality of signal ears, ground ears, and clustered pillars that can be arranged in relation to a base plate such that each component of the antenna can be manufactured from a single piece of material, thereby allowing for the use of additive manufacturing techniques which can substantially reduce the cost and time of the manufacturing process. The phased array can include a signal ear that include one or more posts that interface with an airgap located within a base plate of the array, wherein the size of the airgap in relation to the size of the post is configured to achieve an optimal level of impedance matching.

FIELD OF THE DISCLOSURE

The present disclosure relates generally to antennas, and morespecifically to antenna arrays that are specifically configured toutilize low-cost and efficient manufacturing processes to produceultra-wideband, multi-band, phased array or electronically scanned arrayantennas.

BACKGROUND OF THE DISCLOSURE

There are increasing demands to develop a wideband phased array orelectronically scanned array (ESA) that include a wide variety ofconfigurations for various applications, such as satellitecommunications (SATCOM), radar, remote sensing, direction finding, andother systems. The goal is to provide more flexibility and functionalityat reduced cost with consideration to limited space, weight, and powerconsumption (SWaP) on modern military and commercial platforms. Thisrequires advances in ESA and manufacturing technologies.

A phased array antenna is an array of antenna elements in which thephases of respective signals feeding the antenna elements are set insuch a way that the effective radiation pattern of the array isreinforced in a desired direction and suppressed in undesireddirections, thus forming a beam. The relative amplitudes of constructiveand destructive interference effects among the signals radiated by theindividual elements determine the effective radiation pattern of thephased array. The number of antenna elements in a phased array antennais often dependent on the required gain of a particular application andcan range from isotropic to highly directive levels.

Phased array antennas for ultra-wide bandwidth (more than one octavebandwidth) performance are often large, causing excessive size, weight,and cost for applications requiring many elements. The excessive size ofan array may be required to accommodate “electrically large” radiatingelements (several wavelengths in length), increasing the total depth ofthe array. Arrays may also be large due to the nesting of severalmulti-band elements to enable instantaneous ultra-wide bandwidthperformance, which increases the total length and width of the array.

Because arrays are often large and include many individual elements, theprocess for manufacturing an antenna array can be expensive and requirea great deal of time and labor. Traditionally, antenna arrays arecreated using multiple components that are often made from differenttypes of materials thus requiring that each individual component bemanufactured separately. Once each component has been manufacturedseparately, the components have to be assembled in a specificconfiguration to build the array. The assembly process itself can betime consuming and arduous.

An antenna array that can limit the number of different materialsrequired to manufacture the components thus being able to utilize alow-cost and efficient manufacturing process would substantially lowerthe cost, labor, and time required to create complex antenna arrays.

SUMMARY OF THE DISCLOSURE

A phased array antenna that is configured to allow for substantiallyeach and every component of the phased array to be manufactured usingmetal or another material that can be conductively plated is provided.The phased array can include a plurality of signal ears, ground ears,and clustered pillars that can be arranged in relation to a base platesuch that each component of the antenna can be manufactured from asingle piece of material, thereby allowing for the use of additivemanufacturing techniques which can substantially reduce the cost andtime of the manufacturing process. The phased array can include a signalear that include one or more posts that interface with an airgap locatedwithin a base plate of the array, wherein the size of the airgap inrelation to the size of the post is configured to achieve an optimallevel of impedance matching.

In additional embodiments, the phased array can be further improved bybeing configured to include a clustered pillar to promoteelectromagnetic coupling between adjacent elements of the phase array.The shape of the clustered pillar can be configured to allow forincreased coupling between adjacent elements, thereby allowing for arelaxed lattice spacing in the array. In additional embodiments, theradiating elements can be configured such that the mutual couplingbetween adjacent elements is sufficiently strong so as to not require aclustered pillar.

In additional embodiments, the phased array antenna can be furtherimproved by designing the elements of the phased array to mate with acoaxial cable and PCB circuit thereby providing more flexibility to testthe aperture using only coaxial cables or to excite the entire arrayusing a PCB combiner. In some embodiments, the phased array can also beimproved by providing the elements of the phased array to mate with aplurality of Subminiature Version A (SMA) connectors.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A illustrates a plan view of a general dual-polarized phased arrayantenna according to examples of the disclosure.

FIG. 1B is a unit cell of a general dual-polarized phased array antennaaccording to examples of the disclosure.

FIG. 2A is an isometric view of a dual-polarized phased array antennaaccording to examples of the disclosure.

FIG. 2B is a top view of a dual-polarized phased array antenna accordingto examples of the disclosure.

FIG. 2C is an isometric view of a unit cell of a dual-polarized phasedarray antenna according to examples of the disclosure.

FIG. 3A is an isometric view of a unit cell of dual-polarized phasedarray antenna according to examples of the disclosure.

FIG. 3B is a side view of a unit cell of dual-polarized phased arrayantenna according to examples of the disclosure.

FIG. 3C is a top view of a unit cell of dual-polarized phased arrayantenna according to examples of the disclosure.

FIG. 4A is an isometric view of a radiating element of a phased arrayantenna according to examples of the disclosure.

FIG. 4B is an isometric view of a unit cell of a single-polarizedassembly of a phased array antenna according to examples of thedisclosure.

FIG. 5A is an isometric view of a unit cell of a dual-polarized phasedarray antenna with dielectric sleeve according to examples of thedisclosure.

FIG. 5B is a side view of a unit cell of a dual-polarized phased arrayantenna with dielectric sleeve according to examples of the disclosure.

FIG. 5C is a cross-sectional view of a built-in radiating element RFinterconnect/connector according to examples of the disclosure.

FIG. 5D is a top view of a unit cell of a dual-polarized phased arrayantenna with dielectric sleeve according to examples of the disclosure.

FIG. 6A is a three-dimensional view of a dual-polarized phased arrayantenna according to examples of the disclosure.

FIG. 6B is a three-dimensional view of a radiating element of a phasedarray antenna according to examples of the disclosure.

FIG. 7A is an isometric view of a single-polarized phased array antennaaccording to examples of the disclosure.

FIG. 7B is an isometric view of a unit cell of a single-polarized phasedarray antenna according to examples of the disclosure.

FIG. 7C is a top view of a unit cell of a single-polarized phased arrayantenna according to examples of the disclosure.

FIG. 8A is an isometric view of a dual-polarized phased array antennaaccording to examples of the disclosure.

FIG. 8B is an isometric view of a unit cell of a dual-polarized phasedarray antenna according to examples of the disclosure.

FIG. 8C is a top view of a unit cell of a dual-polarized phased arrayantenna according to examples of the disclosure.

FIGS. 9A-B illustrates a phased array and corresponding unit cell inwhich the components are shaped so as to provide increased couplingbetween a clustered pillar and the radiating element according toexamples of the disclosure.

FIGS. 10A-C illustrate a phased array with relaxed lattice spacing thatutilizes the radiating element of FIG. 9 according to examples of thedisclosure.

FIG. 11 illustrates a phased array in which the pillars and grounds earsof the radiating elements are integrated into the base plate, and thesignal ear is overmolded according to examples of the disclosure.

FIGS. 12A-B illustrates an element and base plate of the phased arrayconfigured to be mated with an elastomeric gasket that delivers signaland ground to a coaxial connector or PCB according to examples of thedisclosure.

FIG. 13 illustrates the feeding structure of the radiating element inthe base plate of the phased array configured to be mated with a coaxialconnector according to examples of the disclosure.

FIGS. 14A-B illustrate an exemplary feeding structure of a radiatingelement in the base plate of the phased array configured to be matedwith an elastomeric gasket according to examples of the disclosure.

FIG. 15 illustrates an embodiment of the interface at the base plate toinstall the elastomeric gasket according to examples of the disclosure.

FIGS. 16A-B illustrates an exemplary RF interconnect with PCB or acoaxial cable.

FIG. 17A-B illustrates a phased array and corresponding unit cell inwhich the components are formed from a single material so as utilize anadditive manufacturing process according to examples of the disclosure.

FIG. 18A illustrates a side view of an exemplary all-metal unit cell ofa phased array antenna according to examples of the disclosure.

FIG. 18B illustrates a top view of an exemplary all-metal unit cell of aphase array antenna according to examples of the disclosure.

FIGS. 19A-C illustrate exemplary pillar configurations for a phasedarray antenna with all-metal unit cells according to examples of thedisclosure.

FIG. 20 illustrates an isometric view of a phased array antenna withall-metal unit cells and with a triangular clustered pillarconfiguration according to examples of the disclosure.

FIG. 21 illustrates a side view of a phased array antenna with all metalunit cells and with a mixed clustered pillar arrangement according toexamples of the disclosure.

FIG. 22 illustrates an exemplary RF interconnect with PCB or a coaxialcable for a phased array that utilizes an all-metal unit cell accordingto examples of the disclosure.

FIG. 23 illustrates an exemplary method for manufacturing an all-metalphased array according to examples of the disclosure

DETAILED DESCRIPTION OF THE INVENTION

In the following description of the disclosure and embodiments,reference is made to the accompanying drawings in which are shown, byway of illustration, specific embodiments that can be practiced. It isto be understood that other embodiments and examples can be practicedand changes can be made without departing from the scope of thedisclosure.

In addition, it is also to be understood that the singular forms “a,”“an,” and “the” used in the following description are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It is also to be understood that the term “and/or” as usedherein refers to and encompasses any and all possible combinations ofone or more of the associated listed items. It is further to beunderstood that the terms “includes, “including,” “comprises,” and/or“comprising,” when used herein, specify the presence of stated features,integers, steps, operations, elements, components, and/or units, but donot preclude the presence or addition of one or more other features,integers, steps, operations, elements, components, units, and/or groupsthereof.

Reference is sometimes made herein to an array antenna having aparticular configuration (e.g. a planar array). One of ordinary skill inthe art would appreciate that the techniques described herein areapplicable to various sizes and shapes of array antennas. It should thusbe noted that although the description provided herein describes theconcepts in the context of a rectangular array antenna, those ofordinary skill in the art would appreciate that the concepts equallyapply to other sizes and shapes of array antennas including, but notlimited to, arbitrarily shaped planar array antennas as well ascylindrical, conical, spherical and arbitrarily shaped conformal arrayantennas.

Reference is also made herein to the array antenna including radiatingelements of a particular size and shape. For example, certainembodiments of radiating element are described having a shape and a sizecompatible with operation over a particular frequency range (e.g. 2-30GHz). Those of ordinary skill in the art would recognize that othershapes of antenna elements may also be used and that the size of one ormore radiating elements may be selected for operation over any frequencyrange in the RF frequency range (e.g. any frequency in the range frombelow 20 MHz to above 50 GHz).

Reference is sometimes made herein to generation of an antenna beamhaving a particular shape or beam width. Those of ordinary skill in theart would appreciate that antenna beams having other shapes and widthsmay also be used and may be provided using known techniques such as byinclusion of amplitude and phase adjustment circuits into appropriatelocations in an antenna feed circuit.

Described herein are embodiments of frequency-scaled ultra-wide spectrumphased array antennas. These phased array antennas are formed ofrepeating cells of frequency-scaled ultra-wide spectrum radiatingelements. Phased array antennas according to certain embodiments exhibitvery low profile, wide bandwidth, low cross-polarization, and highscan-volume while being low cost, small aperture, modular with built-inRF interconnect, and scalable.

A unit cell of a frequency-scaled ultra-wide spectrum phased arrayantenna, according to certain embodiments, includes a pattern ofradiating elements. According to certain embodiments, the radiatingelements are formed of substrate-free, interlacing components thatinclude a pair of metallic ears that form a coplanar transmission line.One of the ears is the ground component of the radiating element and canbe terminated to the ground of a coaxial connector used for connecting afeed line or directly to the array's base plate. The other ear is thesignal or active line of the radiating element and can be connected tothe center of a coaxial feed line. According to certain embodiments, theedge of the radiating elements (the edge of the ears) are shaped toencapsulate a cross-shape metallic clustered pillar, which controls thecapacitive component of the antenna and can allow good impedancematching at the lower-frequency end of the bandwidth, effectivelyincreasing the operational bandwidth. This has the advantage of a phasedarray antenna in which no wideband impedance matching network or specialmitigation to a ground plane is needed. Radiating elements can be fortransmit, receive, or both. Phased array antennas can be built as singlepolarized or dual polarized by implementing the appropriate radiatingelement pattern, as described below.

FIG. 1A illustrates an antenna array of radiating elements 100 accordingto certain embodiments. A dual polarized configuration is shown withradiating elements oriented both horizontally 106 and vertically 104. Inthis embodiment, a unit cell 102 includes a single horizontallypolarized element 110 and a single vertically polarized element 108(FIG. 1B). Array 100 is a 4×3 array of unit cells 102. According tocertain embodiments, array 100 can be scaled up or down to operate overa specified frequency range. More unit cells can be added to meet otherspecific design requirements such as antenna gain. According to certainembodiments, modular arrays of a predefined size may be combined into adesired configuration to create an antenna array to meet the requiredperformance. For example, a module may include the 4×3 array ofradiating elements 100 illustrated in FIG. 1A. A particular antennaapplication requiring 96 radiating elements can be built using eightmodules fitted together (thus, providing the 96 radiating elements).This modular design allows for antenna arrays to be tailored to specificdesign requirements at a lower cost.

As shown in FIG. 1B, element 108 is disposed along a first axis andelement 110 is disposed along a second axis that is orthogonal to thefirst axis, such that element 108 is substantially orthogonal to element110. This orthogonal orientation results in each unit cell 102 beingable to generate orthogonally directed electric field polarizations.That is, by disposing one set of elements (e.g. vertical elements 104)in one polarization direction and disposing a second set of elements(e.g. horizontal elements 106) in the orthogonal polarization direction,an antenna which can generate signals having any polarization isprovided. In this particular example, unit cells 102 are disposed in aregular pattern, which here corresponds to a square grid pattern. Thoseof ordinary skill in the art would appreciate that unit cells 102 neednot all be disposed in a regular pattern. In some applications, it maybe desirable or necessary to dispose unit cells 102 in such a way thatelements 108 and 110 of each unit cell 102 are not aligned between everyunit cell 102. Thus, although shown as a square lattice of unit cells102, it would be appreciated by those of ordinary skill in the art, thatantenna 100 could include but is not limited to a rectangular ortriangular lattice of unit cells 102 and that each of the unit cells canbe rotated at different angles with respect to the lattice pattern.

Symmetric Phased Array

An array of radiating elements 200 according to certain embodiments isillustrated in FIGS. 2A and 2B. Array 200 is a dual-polarizedconfiguration with multiple columns of radiating elements 204 orientedalong a first polarization axis (referred to herein as verticallypolarized) and multiple rows of radiating elements 206 oriented along asecond polarization axis (referred to herein as horizontally polarized)affixed to base plate 214. A unit cell 202 of array 200 is shown indetail in FIG. 2C. Unit cell 202 includes two radiating elements, avertically polarized radiating element 208 and a horizontally polarizedradiating element 210. Horizontally polarized radiating element 210includes signal ear 216 and ground ear 218. A signal beam is generatedby exciting radiating element 210, i.e. by generating a voltagedifferential between signal ear 216 and ground ear 218. The generatedsignal beam has a direction along the centerline 211 of radiatingelement 210, perpendicular to base plate 214. Centerline 211 is thephase center of radiating element 210. A signal beam generated byexciting radiating element 208, has a phase center midway between itsrespective signal and ground ear. As shown in the embodiments of FIGS.2A-2C, the phase centers of radiating elements 204 are not co-locatedwith the phase centers of radiating elements 206.

In the embodiments of FIG. 2, the radiating elements 204 are of the samesize, shape, and spacing as radiating elements 206. However, phasedarray antennas according to other embodiments, may include only singlepolarized radiating elements (e.g., only rows of radiating elements206). According to some embodiments, the spacing of one set of radiatingelements (e.g., the horizontally polarized elements 206) is differentfrom the spacing of the other set of radiating elements (e.g., thevertically polarized elements 204). According to some embodiments, theradiating element spacing within a row may not be uniform. For example,the spacing between first and second elements within a row may bedifferent than the spacing between the second and third elements.

FIGS. 3A, 3B, and 3C provide enlarged views of unit cell 202 accordingto certain embodiments. Radiating element 208 includes signal ear 220and ground ear 222. Clustered pillar 212 and ground ear 222 may be bothelectrically coupled to base plate 214 such that no (or minimal)electrical potential is generated between them during operation. Signalear 220 is electrically isolated (insulated) from base plate 214,clustered pillar 212, and ground ear 222. According to certainembodiments, a second set of radiating elements 210 are disposed along asecond, orthogonal axis. Radiating element 210 includes signal ear 216and ground ear 218. Clustered pillar 212 and ground ear 218 may be bothelectrically coupled to base plate 214 such that no (or minimal)electrical potential is generated between them during operation.According to certain embodiments, clustered pillar 212 and ground ear218 are not electrically connected to base plate 214 but instead to aseparate ground circuit. Signal ear 216 is electrically isolated(insulated) from base plate 214, clustered pillar 212, and ground ear218.

According to certain embodiments, the edges of the radiating elements(the edge of the ears) are shaped to encapsulate cross-shaped metallicclustered pillar 212 to capacitively couple adjacent radiating elementsduring operation. This can enhance the capacitive component of theantenna, which allows a good impedance match at the low-frequency end ofthe bandwidth. Through this coupling of clustered pillar 212, eachradiating element in a row or column is electromagnetically coupled toground and the previous and next radiating element in the row or column.

Capacitive coupling is achieved by maintaining a gap 320 between aradiating element ear and its adjacent clustered pillar, which createsinterdigitated capacitance between the two opposing surfaces of gap 320.This capacitance can be used to improve the impedance matching of theantenna. Capacitive coupling can be controlled by changing theoverlapped surface area of gap 320 and width of gap 320 (generally,higher capacitance is achieved with larger surface area and less width).According to certain embodiments, signal ears 220 and 216 and groundears 222 and 218 wrap around the cross shape of clustered pillar 212 inorder to maximize the surface area. However, other designs formaximizing the capacitive surface area are also contemplated. Forexample, a clustered pillar and adjacent ear can form interlacingfingers when viewed from above (e.g., the view of FIG. 3C) orinterlacing fingers when viewed from the side (e.g., the view of FIG.3B). According to certain embodiments, gap 320 is less than 0.1 inches,preferably less than 0.05 inches, and more preferably less than 0.01inches. According to some embodiments, gap 320 may be scaled withfrequency (for example, gap 320 may be a function of the wavelength ofthe highest designed frequency, λ). For example, according to someembodiments, gap 320 can be less than 0.05λ, less than 0.025λ, or lessthan 0.013λ. According to some embodiments, gap 320 is greater than0.005λ, greater than 0.01λ, greater than 0.025λ, greater than 0.05λ, orgreater than 0.1λ. As shown in FIG. 3B, according to certainembodiments, the radiating ears include stem portions 370 extending frombase plate 214 to comb portions 380 that include a plurality ofirregularly shaped projections 382. According to certain embodiments,gap 320 extends perpendicularly to base plate 214 (i.e., along thelength of the clustered pillar/radiating element) for the same distanceand located adjacent comb portion 380.

Interdigitated capacitance enables some coupling between adjacentradiating elements in a row (or column). In other words, theelectromagnetic field from a first radiating element communicates fromits ground ear across the adjacent gap to the adjacent clustered pillarthrough the interdigitated capacitance and then across the opposite gapto the adjacent signal ear of the next radiating element. Referring toFIGS. 3A and C, which shows a top view of unit cell 202, clusteredpillar 212 is surrounded by four radiating element ears. On the rightside is signal ear 216 of radiating element 210. On the left side is theground ear 324 of the next radiating element along that axis. On the topside is signal ear 220 of radiating element 208. On the bottom side isthe ground ear 326 of the next radiating element along that axis.Capacitive coupling between clustered pillar 212 and each ear 216 and324 created by adjacent gaps 320 enable the electromagnetic field ofradiating element 208 to couple to the electromagnetic field of the nextradiating element (the radiating element of ground ear 324), andcapacitive coupling between clustered pillar 212 and each ear 220 and326 created by respective adjacent gaps 320 enable the electromagneticfield of radiating element 210 to couple to the electromagnetic field ofthe next radiating element (the radiating element that includes groundear 326).

It should be understood that the illustrations of unit cell 202 in 2C,3A, 3B, and 3C truncate ground ears 324 and 326 on the left and bottomside of clustered pillar 212 for illustrative purposes only. One ofordinary skill in the art would understand that the relative orientationof one set of radiating elements to an orthogonal set of radiatingelements, as described herein, is readily modified, i.e. a signal earcould be on the left side of clustered pillar 212 with a ground earbeing on the right side, and/or a signal ear could be on the bottom sideof clustered pillar 212 with a ground ear being on the top side(relative to the view of FIG. 3C).

According to certain embodiments, base plate 214 is formed from one ormore conductive materials, such as metals like aluminum, copper, gold,silver, beryllium copper, brass, and various steel alloys. According tocertain embodiments, base plate 214 is formed from a non-conductivematerial such as various plastics, including Acrylonitrile butadienestyrene (ABS), Nylon, Polyamides (PA), Polybutylene terephthalate (PBT),Polycarbonates (PC), Polyetheretherketone (PEEK), Polyetherketone (PEK),Polyethylene terephthalate (PET), Polyimides, Polyoxymethylene plastic(POM/Acetal), Polyphenylene sulfide (PPS), Polyphenylene oxide (PPO),Polysulphone (PSU), Polytetrafluoroethylene (PTFE/Teflon), orUltra-high-molecular-weight polyethylene (UHMWPE/UHMW), that is platedor coated with a conductive material such as gold, silver, copper, ornickel. According to certain embodiments, base plate 214 is a solidblock of material with holes, slots, or cut-outs to accommodateclustered pillars 212, signal ears 216 and 220, and ground ears 218 and222 on the top (radiating) side and connectors on the bottom side toconnect feed lines. In other embodiments, base plate 214 includescutouts to reduce weight.

According to certain embodiments, base plate 214 is designed to bemodular and includes features in the ends that can mate with adjoiningmodules. Such interfaces can provide both structural rigidity andcross-interface conductivity. Modules may be various sizes incorporatingvarious numbers of unit cells of radiating elements. According tocertain embodiments, a module is a single unit cell. According tocertain embodiments, modules are several unit cells (e.g., 2×2, 4×4),dozens of unit cells (e.g., 5×5, 6×8), hundreds of unit cells (e.g.,10×10, 20×20), thousands of unit cells (e.g., 50×50, 100×100), tens ofthousands of unit cells (e.g., 200×200, 400×400), or more. According tocertain embodiments, a module is rectangular rather than square (i.e.,more cells along one axis than along the other).

According to certain embodiments, modules align along the centerline ofa radiating element such that a first module ends with a groundclustered pillar and the next module begins with a ground clusteredpillar. The base plate of the first module may include partial cutoutsalong its edge to mate with partial cutouts along the edge of the nextmodule to form a receptacle to receive the radiating elements that fitbetween the ground clustered pillars along the edges of the two modules.According to certain embodiments, the base plate of a module extendsfurther past the last set of ground clustered pillars along one edgethan it does along the opposite edge in order to incorporate a last setof receptacles used to receive the set of radiating elements that formthe transition between one module and the next. In these embodiments,the receptacles along the perimeter of the array remain empty. Accordingto certain embodiments, a transition strip is used to join modules, withthe transition strip incorporating a receptacle for the transitionradiating elements. According to certain embodiments, no radiatingelements bridge the transition from one module to the next. Arraysformed of modules according to certain embodiments can include variousnumbers of modules, such as two, four, eight, ten, fifteen, twenty,fifty, a hundred, or more.

In some embodiments, base plate 214 may be manufactured in various waysincluding machined, cast, or molded. In some embodiments, holes orcut-outs in base plate 214 may be created by milling, drilling, formedby wire EDM, or formed into the cast or mold used to create base plate214. Base plate 214 can provide structural support for each radiatingelement and clustered pillar and provide overall structural support forthe array or module. Base plate 214 may be of various thicknessesdepending on the design requirements of a particular application. Forexample, an array or module of thousands of radiating elements mayinclude a base plate that is thicker than the base plate of an array ormodule of a few hundred elements in order to provide the requiredstructural rigidity for the larger dimensioned array. According tocertain embodiments, the base plate is less than 6 inches thick.According to certain embodiments, the base plate is less than 3 inchesthick, less than 1 inch thick, less than 0.5 inches thick, less than0.25 inches thick, or less than 0.1 inches thick. According to certainembodiments, the base plate is between 0.2 and 0.3 inches thick.According to some embodiments, the thickness of the base plate may bescaled with frequency (for example, as a function of the wavelength ofthe highest designed frequency, λ). For example, the thickness of thebase plate may be less than 1.0λ, 0.5λ, or less than 0.25λ. According tosome embodiments, the thickness of the base plate is greater than 0.1λ,greater than 0.25λ, greater than 0.5λ, or greater than 1.0λ.

According to certain embodiments, radiating ears 216, 218, 220 and 222and clustered pillar 212 may be formed from any one or more materialssuitable for use in a radiating antenna. These may include materialsthat are substantially conductive and that are relatively easy tomachine, cast and/or solder or braze. For example, one or more radiatingears 216, 218, 220 and 222 and clustered pillar 212 may be formed fromcopper, aluminum, gold, silver, beryllium copper, or brass. In someembodiments, one or more radiating ears 216, 218, 220 and 222 andclustered pillar 212 may be substantially or completely solid. Forexample, one or more radiating ears 216, 218, 220 and 222 and clusteredpillar 212 may be formed from a conductive material, for example,substantially solid copper, brass, gold, silver, beryllium copper, oraluminum. In other embodiments, one or more radiating ears 216, 218, 220and 222 and clustered pillar 212 are substantially formed fromnon-conductive material, for example plastics such as ABS, Nylon, PA,PBT, PC, PEEK, PEK, PET, Polyimides, POM, PPS, PPO, PSU, PTFE, orUHMWPE, with their outer surfaces coated or plated with a suitableconductive material, such as copper, gold, silver, or nickel.

In other embodiments, one or more radiating ears 216, 218, 220 and 222and clustered pillar 212 may be substantially or completely hollow, orhave some combination of solid and hollow portions. For example, one ormore radiating ears 216, 218, 220 and 222 and clustered pillar 212 mayinclude a number of planar sheet cut-outs that are soldered, brazed,welded or otherwise held together to form a hollow three-dimensionalstructure. According to some embodiments, one or more radiating ears216, 218, 220 and 222 and clustered pillar 212 are machined, molded,cast, or formed by wire-EDM. According to some embodiments, one or moreradiating ears 216, 218, 220 and 222 and clustered pillar 212 are 3Dprinted, for example, from a conductive material or from anon-conductive material that is then coated or plated with a conductivematerial.

Referring now to FIGS. 3A, 4A, and 4B, a method of manufacturing anarray according to certain embodiments will be described. Base plate214, radiating ears 216, 218, 220 and 222, and clustered pillar 212 areeach separate pieces that may be manufactured according to the methodsdescribed above. Clustered pillar 212 is assembled to base plate 214 bywelding or soldering onto base plate 214. In some embodiments, clusteredpillar 212 is press fit (interference fit) into a hole in base plate214. According to certain embodiments, clustered pillar 212 is screwedinto base plate 214. For example, male threads may be formed into thebottom portion of clustered pillar 212 and female threads may be formedinto the receiving hole in base plate 214. According to certainembodiments, clustered pillar 212 is formed with a pin portion at itsbase that presses into a hole in base plate 214. According to certainembodiments, a bore is machined into clustered pillar 212 at the base toaccommodate an end of a pin and a matching bore is formed in base plate214 to accommodate the other end of the pin. Then the pin is pressedinto the clustered pillar 212 or the base plate 214 and the clusteredpillar 212 is pressed onto the base plate 214.

Referring to FIGS. 4A and 4B, a radiating element is assembled as asub-assembly, which is inserted into base plate 214, according tocertain embodiments. Signal ear 416 and ground ear 418 are separatepieces formed according to one or more methods including those describedabove. Signal ear 416 and ground ear 418 are assembled to plug 428. Plug428 may be formed of a dielectric material, such as plastic, in order tomaintain the electrical isolation of signal ear 416 from ground ear 418and base plate 414. Plug 428 may be formed from various plastics such asABS, Nylon, PA, PBT, PC, PEEK, PEK, PET, Polyimides, POM, PPS, PPO, PSU,or UHMWPE. Preferably, plug 428 is formed of resin, PTFE, or polylacticacid (PLA). According to certain embodiments, signal ear 416 and groundear 418 are inserted into receptacles in plug 428, for example bypress-fitting, to form assembly 440. According to other embodiments,plug 428 is molded around signal ear 416 and ground ear 418. Assembly440 may then be assembled to the base plate 414 by sliding betweenclustered pillars 412 and 430 that have been previously assembled tobase plate 414, for example, according to the methods described above.Plug 428 can then fit into a hole or bore in base plate 414, for exampleby press fitting. Plug 428 may be designed to not only providestructural support for signal ear 416 and ground ear 418 and but alsofor impedance transformation to mate with a coaxial connector, asdescribed in more detail below.

Referring now to FIGS. 3A and 3C, gap 320 may be an airgap or it may beprovided by a dielectric material, or a combination of both. Asdescribed above, gap 320 may be minimized in order to maximize thecapacitive coupling of ground clustered pillar 212 with the adjacentradiating elements (e.g., 208 and 210). Minimizing gap 320 can bedifficult when assembling multiple different components (e.g. base plate214, clustered pillar 212, ears 220 and 216), each with their ownmanufacturing tolerances. Furthermore, the antenna array (e.g., array200) may be subject to vibration that may cause adjacent radiatingelements ears to contact clustered pillar 212 causing a short circuit.To manage these issues, according to certain embodiments, gap 320 iscreated and maintained by providing a dielectric coating (not shown) onclustered pillar 214. According to certain embodiments, dielectriccoatings may be epoxy coatings, PTFE, or a melt processablefluoropolymer applied using, for example, a spraying or dipping process.

According to certain embodiments, for example as shown in FIGS. 5A, 5B,and 5D, gap 520 is created or maintained by dielectric sleeve 550 thatslides over clustered pillar 512. Sleeve 550 may be formed from variousdielectric materials such as plastics like ABS, Nylon, PA, PBT, PC,PEEK, PEK, PET, Polyimides, POM, PPS, PPO, PSU, PTFE, or UHMWPE. Sleeve550 may made from a high strength plastic in order to minimize wallthickness. According to certain embodiments, sleeve 550 is formed from aheat shrink material, such as nylon or polyolefin, in the form of a tubethat slides over clustered pillar 512, which is heated to shrink ontoclustered pillar 512. According to certain embodiments, sleeve 550 is 3Dprinted from a polymer. Sleeve 550 is preferably designed with minimalwall thickness. According to certain embodiments, the thickness ofsleeve 550 is less than 0.1 inches, preferably less than 0.05 inches,and more preferably less than 0.01 inches.

FIG. 5C illustrates a feed arrangement for providing the excitation toradiating element 502 according to certain embodiments. As describedabove, a radio beam is generated by creating an electrical potentialbetween signal ear 516 and ground ear 518. This electrical potential iscreated by feeding voltage to signal ear 516 and grounding ground ear518. According to certain embodiments, signal ear 516 is fed byconnecting a coaxial cable to a coaxial connector 530 embedded orinserted in the bottom of base plate 514. Signal ear 516 is electricallyconnected to the center line inside plug 528. According to someembodiments, signal ear 516 forms the center line inside plug 528.Signal ear 516 is electrically connected to the inner conductor (coreline) of a feed line through coaxial connector 530 as shown in FIG. 5C.

According to certain embodiments, connector 530 is a female connector.Base plate 514 may be electrically connected to the outer conductor(shield) of the coaxial cable through the body of coaxial connector 530.According to certain embodiments, ground ear 518 is directlyelectrically connected to the outer conductor of the coaxial cablethrough a ground conductor of coaxial connector 530. In otherembodiments, ground ear 518 is inserted or formed into a side of plug528 such that a portion of the ground ear is exposed, as depicted inFIGS. 5A and 5C. When plug 528 is inserted into base plate 514, theexposed side of ground ear 518 makes contact with base plate 514. Groundear 518 is then electrically connected to base plate 514, which is inturn, electrically connected to ground through, for example, coaxialconnector 530 or some other grounding means.

According to certain embodiments, signal ear 516, ground ear 518, plug528, and connector 530 are built together as a subassembly that may thenbe assembled into base plate 514. According to certain embodiments, thecenter conductor of coaxial connector 530 and signal ear 516 are formedfrom a single piece of material. According to certain embodiments,connector 530 is embedded within base plate 528 (as shown in FIG. 5C).According to some embodiments, connector 530 protrudes from the bottomof base plate 528, protrudes from a recess in the bottom of base plate514 or is affixed to the bottom plane of base plate 514. According tosome embodiments, connector 530 is an off-the-shelf male or femaleconnector, and according to other embodiments, connector 530 is custombuilt or modified for fitting into base plate 514. According to certainembodiments, connector 530 is designed to be directly attached to a feedline. According to other embodiments, connector 530 is attached to afeed line through an intermediate manifold that, itself, directlyconnects to feed lines.

FIGS. 6A, 6B, and 6C illustrate an antenna array 600 according tocertain embodiments. Base plate 614 is formed from a block of aluminum.Clustered pillars 612 are machined directly into base plate 614 allowingfor relatively good positional tolerances. A 3D printed dielectricsleeve 650 covers the ends of each clustered pillar 612. Radiatingelement assembly 608 is shown in FIG. 6B. In this figure, each ear 216and 218 is formed of beryllium copper that has been shaped using wireEDM. Plug 628 is formed from a plastic such as resin, Teflon, or PLAthat is molded around ears 216 and 218. Ground ear 218 is positioned onthe side of plug 628 such that when the assembly 640 is assembled tobase plate 614, ground ear 618 contacts the bore in base plate 614, thuscreating a conducting path. Assembly 640 is assembled to base plate 614by pressing plug 628 into the receiving bore or cut-out in base plate614, for example using a slight interference fit. According to certainembodiments, plug 628 has an oblong shape that is longer in onedirection than in the orthogonal direction to maintain the orientationof the ears along the axis of the relative row such that the capacitivecoupling portion of the ears mate with the sleeve covered, cross shapedprotrusions of the clustered pillar 612.

Returning to the examples of FIGS. 2A-2C, the phased array antenna 200,according to certain embodiments, has a designed operational frequencyrange, e.g., 1 to 30 GHz, 2 to 30 GHz, 3 to 25 GHz, and 3.5 to 21.5 GHz.According to certain embodiments, the phased array antenna is designedto operate at a frequency of at least 1 GHz, at least 2 GHz, at least 3GHz, at least 5 GHz, at least 10 GHz, at least 15 GHz, or at least 20GHz. According to certain embodiments, the phased array antenna isdesigned to operate at a frequency of less than 50 GHz, less than 40GHz, less than 30 GHz, less than 25 GHz, less than 22 GHz, less than 20GHz, or less than 15 GHz. The sizing and positioning of radiatingelements can be designed to effectuate these desired frequencies andranges. For example, the spacing between a portion of a first radiatingelement and the portion of the next radiating element along the sameaxis may be equal to or less than about one-half a wavelength, λ, of adesired frequency (e.g., highest design frequency). According to someembodiments, the spacing may be less than 1λ, less than 0.75λ, less than0.66λ, less than 0.33λ, or less than 0.25λ. According to someembodiments, the spacing may be equal to or greater than 0.25λ, equal toor greater than 0.5λ, equal to or greater than 0.66λ, equal to orgreater than 0.75λ, or equal to or greater than 1λ.

Additionally, the height of radiating element 208 and 210 may be lessthan about one-half the wavelength of the highest desired frequency.According to some embodiments, the height may be less than 1λ, less than0.75λ, less than 0.66λ, less than 0.33λ, or less than 0.25λ. Accordingto some embodiments, the height may be equal to or greater than 0.25λ,equal to or greater than 0.5λ, equal to or greater than 0.66λ, equal toor greater than 0.75λ, or equal to or greater than 1λ. For example,according to certain embodiments where the operational frequency rangeis 2 GHz to 14 GHz, with the wavelength at the highest frequency, 14GHz, being about 0.84 inches, the spacing from one radiating element toanother radiating element is less than about 0.42 inches. According tocertain embodiments, for this same operating range, the height of aradiating element from the base plate is less than about 0.42 inches.

As another example, according to certain embodiments where theoperational frequency range is 3.5 GHz to 21.5 GHz, with the wavelengthat the highest frequency, 21.5 GHz, being about 0.6 inches, the spacingfrom one radiating element to another radiating element is less thanabout 0.3 inches. According to certain embodiments, for this sameoperating range, the height of a radiating element from the base plateis less than about 0.3 inches. It should be appreciated decreasing theheight of the radiating elements can improve the cross-polarizationisolation characteristic of the antenna. It should also be appreciatedthat using a radome (an antenna enclosure designed to be transparent toradio waves in the operational frequency range) can provideenvironmental protection for the array. The radome may also serve as awide-angle impedance matching (WAIM) that improves the voltage standingwave ration (VSWR) of the array at wide-scan angles (improves theimpedance matching at wide-scan angles).

According to certain embodiments, more spacing between radiatingelements eases manufacturability. However, as described above, a maximumspacing can be selected to prevent grating lobes at the desired scanvolumes. According to certain embodiments, the selected spacing reducesthe manufacturing complexity, sacrificing scan volume, which may beadvantageous where scan volume is not critical.

According to certain embodiments, the size of the array is determined bythe required antenna gain. For example, for certain application over40,000 elements are required. For another example, an array of 128elements may be used for bi-static radar.

Asymmetric Phased Array

According to certain embodiment an asymmetric design is employed toincrease the manufacturability of the phased array antenna. FIGS. 7A,7B, and 7C illustrate a single polarized array 700 according to certainembodiments employing an asymmetric design. Each radiating element 710includes a pair of metallic ears (716 and 718) that form a coplanartransmission line. Ground ear 718 is formed into the same block ofmaterial as base plate 714 and clustered pillars 712 and 730 and iseffectively electrically terminated directly to base plate 714. As inthe symmetric design described above, signal ear 716 can be connected tothe center of a coaxial feed line. The edge of signal ear 716 is shapedto encapsulate clustered pillar 712, but the edge of ground ear 718 issubstantially planar and does not wrap around clustered pillar 712. Thisenables ground ear 718 to be easily machined into the same base platematerial or otherwise easily formed along with base plate 714.

Following is a description of the asymmetric design, according tocertain embodiments. A unit cell of the phased array antenna is shown inFIG. 7B with a top view shown in FIG. 7C. As shown, for example on theright-hand side of FIG. 7C, ground ear 718 is shaped differently on itscapacitive coupling side than, for example, ground ear 418 in FIG. 4A.The capacitive coupling surface is flattened. This enables ground ear418 to be machined into base plate 712, i.e. base plate 712 and groundear 718 are machined into the same block of material. Additionally,according to certain embodiments, clustered pillar 730 has an irregularshape (as opposed to the regular cross shape of clustered pillar 212 inFIG. 3C, for example). The portion of clustered pillar 730 thatcapacitively couples with ground ear 718 is also flattened or planar tomatch clustered pillar 730. As shown on the right side of FIG. 7C,signal ear 716 has the same shape as the signal ear described above andthe right side of clustered pillar 712 has the same cross shape asdescribed in the sections above. This asymmetry enables base plate 714,clustered pillars 712 and 760, and ground ear 718 to be machined, orotherwise formed from the same piece of material increasingmanufacturability by reducing the number of pieces, the assembly time,and tolerance stack-up effects while also maintaining performance.

According to certain embodiments, an asymmetric design is employed for adual-polarized phased array antenna as shown in FIGS. 8A, 8B, and 8C.The same asymmetric configuration can be used for an orthogonal set ofradiating elements 808. As shown in the top view of FIG. 8C, clusteredpillar 862 is surrounded by ground ears 864 and 868 and signal ears 868and 870. Signal ears 868 and 870 include the same or similar u-shapedcapacitive coupling surface described above while ground ears 864 and866 incorporate a planar shape. This asymmetrical design enablesclustered pillar 862 and ground ears 864 and 866 to be formed into thesame piece of material as base plate 814.

According to certain embodiments, base plate 814, the clustered pillars(e.g., 862) and the ground ears (e.g., 864 and 866) are formed fromconductive materials, such as a metal like aluminum, copper, gold,silver, beryllium copper, brass, and various steel alloys. According tocertain embodiments, base plate 814, the clustered pillars (e.g., 862)and the ground ears (e.g., 864 and 866) are formed from a non-conductivematerial such as various plastics, including ABS, Nylon, PA, PBT, PC,PEEK, PEK, PET, Polyimides, POM, PPS, PPO, PSU, PTFE, or UHMWPE, that isplated or coated with a conductive material such as gold, silver,copper, or nickel. According to certain embodiments, base plate 814, theclustered pillars (e.g., 862) and the ground ears (e.g., 864 and 866)are a solid block of material with holes, slots, or cut-outs toaccommodate the signal ears (e.g., 868 and 870) and connectors on thebottom side to connect feed lines. In other embodiments, base plate 814,the clustered pillars (e.g., 862) and the ground ears (e.g., 864 and866) include cutouts to reduce weight.

According to certain embodiments, base plate 814, the clustered pillars(e.g., 862) and the ground ears (e.g., 864 and 866) are designed to bemodular and base plate 814 includes features in the ends to mate withadjoining modules. Such interfaces may be designed to provide bothstructural rigidity and good cross-interface conductivity. In someembodiments, base plate 814, the clustered pillars (e.g., 862) and theground ears (e.g., 864 and 866) can be manufactured in various waysincluding machined, cast, molded, and/or formed using wire-EDM. In someembodiments, holes or cut-outs in base plate 214 may be created bymilling, drilling, wire EDM, or formed into the cast or mold used tocreate base plate 814, the clustered pillars (e.g., 862) and the groundears (e.g., 864 and 866). Base plate 814 may be of various thicknessesdepending on the design requirements of a particular application. Baseplate 814 can provide structural support for each radiating element andclustered pillar as well as provide overall structural support for thearray. For example, an array of thousands of radiating elements may havea base plate that is thicker than that of an array of a few hundredelements in order to provide the required structural rigidity for thelarger dimensioned array. According to certain embodiments, the baseplate is less than 6 inches thick. According to certain embodiments, thebase plate is less than 3 inches thick, less than 1 inch thick, lessthan 0.5 inches thick, less than 0.25 inches thick, or less than 0.1inches thick. According to certain embodiments, the base plate isbetween 0.2 and 0.3 inches thick.

Radiating Element

As described above, radiating elements (e.g., 410 of FIG. 4A), accordingto certain embodiments, include pairs of radiating element ears, aground ear (e.g., 418) and a signal ear (e.g., 418). The design of theradiating elements affects the beam forming and steering characteristicsof the phased array antenna. For example, as discussed above, the heightof the radiating element may affect the operational frequency range. Forexample, the shortest wavelength (corresponding to the highestfrequency) may be equivalent to twice the height of the radiatingelement. In addition to this design parameter, other features of theradiating element can affect bandwidth, cross-polarization, scan volume,and other antenna performance characteristics. According to theembodiment shown in FIG. 4, radiating element 410 includes a symmetricalportion that is symmetrical from just above the top of plug 428 to thetop of element 410 such that the upper portion of ground ear 418 is amirror image of the upper portion of signal ear 416. Each ear includes aconnecting portion for connecting to plug 428, a stem portion 470, and acomb portion 480. Each comb portion 480 includes an inner facingirregular surface 482 and an outward facing capacitive coupling portion484.

An important design consideration in phased array antennas is theimpedance matching of the radiating element. This impedance matchingaffects the achievable frequency bandwidth as well as the antenna gain.With poor impedance matching, bandwidth may be reduced and higher lossesmay occur resulting in reduced antenna gain.

As is known in the art, impedance refers, in the present context, to theratio of the time-averaged value of voltage and current in a givensection of the radiating elements. This ratio, and thus the impedance ofeach section, depends on the geometrical properties of the radiatingelement, such as, for example, element width, the spacing between thesignal ear the ground ear, and the dielectric properties of thematerials employed. If a radiating element is interconnected with atransmission line having different impedance, the difference inimpedances (“impedance step” or “impedance mismatch”) causes a partialreflection of a signal traveling through the transmission line andradiating element. The same can occur between the radiating element andfree space. “Impedance matching” is a process for reducing oreliminating such partial signal reflections by matching the impedance ofa section of the radiating element to the impedance of the adjoiningtransmission line or free space. As such, impedance matching establishesa condition for maximum power transfer at such junctions. “Impedancetransformation” is a process of gradually transforming the impedance ofthe radiating element from a first matched impedance at one end (e.g.,the transmission line connecting end) to a second matched impedance atthe opposite end (e.g., the free space end).

According to certain embodiments, transmission feed lines provide theradiating elements of a phased array antenna with excitation signals.The transmission feed lines may be specialized cables designed to carryalternating current of radio frequency. In certain embodiments, thetransmission feed lines may each have an impedance of 50 ohms. Incertain embodiments, when the transmission feed lines are excitedin-phase, the characteristic impedance of the transmission feed linesmay also be 50 ohms. As understood by one of ordinary skill in the art,it is desirable to design a radiating element to perform impedancetransformation from this 50 ohm impedance into the antenna at theconnector, e.g., connector 530 in FIG. 5C, to the impedance of freespace, given by 120×pi (377) ohms. By designing the radiating element,base plate, plug, and connector to achieve this impedancetransformation, the phased array antenna can be easily coupled to acontrol circuit without the need for intermediate impedancetransformation components.

According to certain embodiments, instead of designing the phased arrayantenna for 50 ohm impedance into connector 530, the antenna is designedfor another impedance into connector 530, such as 100 ohms, 150 ohms,200 ohms, or 250 ohms, for example. According to certain embodiments, aradiating element is designed for impedance matching to some other valuethan free space (377 ohms), for example, when a radome is to be used.

According to certain embodiments, the radiating element is designed tohave optimal impedance transfer from transmission feed line to freespace. It will be appreciated by those of ordinary skill in the art,that the radiating element can have various shapes to effect theimpedance transformation required to provide optimal impedance matching,as described above. The described embodiments can be modified usingknown methods to match the impedance of the fifty ohm feed to freespace.

Referring again to FIG. 5C, according to certain embodiments, connector530, plug 258, and the connecting portions of signal ear 516 and groundear 518 result in impedance at the base of the stem portions of thesignal and ground ears of about 150 ohms. According to some embodiments,this value is between 50 and 150 ohms and in other embodiments, thisvalue is between 150 and 350 ohms. According to certain embodiments, thevalue is around 300 ohms. The shape of the stem and comb portions aredesigned to perform the remaining impedance transformation (e.g., from150 ohm to 377 ohm or from 300 ohm to 377 ohm).

Referring to FIG. 5B, stem portion 570 and 572 of signal ear 516 andground ear 518, respectively, are parallel and spaced apart. Accordingto certain embodiments, the distance between the stem portions is lessthan 0.5 inches, less than 0.1 inches, or less than 0.05. According tocertain embodiments, the spacing is less than 0.025 inches, less than0.02 inches, less than 0.015 inches, or less than 0.010 inches.According to some embodiments, the spacing between stem portions isselected to optimize the impedance matching of the antenna element.According to some embodiments, the spacing is selected based on theconfiguration of a connector embedded in base plate 514. According tosome embodiments, the distance between the stem portions may be scaledwith frequency (for example, the distance may be a function of thewavelength of the highest designed frequency). For example, according tosome embodiments, the distance can be less than 0.05λ, less than 0.025λ,or less than 0.013λ. According to some embodiments, the distance can begreater than 0.001λ, greater than 0.005λ, greater than 0.01λ, or greaterthan 0.05λ.

As shown in FIG. 5B, the comb portion 580 of signal ear 516 includesinner-facing irregular surface 582 and the comb portion 580 of groundear 518 includes inner-facing irregular surface 584. The inner-facingirregular surfaces 582 and 584 are symmetrical and include multiplelobes or projections. The placement and spacing of the lobes affects theimpedance transformation of radiating element 510. According to theembodiment shown in FIG. 5B, these inner-facing surfaces curve away fromthe center line starting near the top of the stem portions 570 and 572into first valleys and then curve toward the centerline into firstlobes. The surfaces then curve away again into second valleys and curvetoward the centerline again into second lobes. From the second lobes,the surfaces curve away again into third valleys and then curve inwardonce more into final lobes. The sizes, shapes, and numbers of theselobes and valleys contribute to the impedance transformation of theradiating element. For example, according to certain embodiments, aradiating element ear includes only one lobe, for example, at the distalend (i.e., inner-facing irregular surface has a “C” shaped profile).

In addition to the shape, the thickness of a radiating element ear mayalso affect the impedance transformation of the radiating element.According to certain embodiments, the thickness is less than 0.5 inchesor less than 0.25 inches. According to certain embodiments, thethickness is preferably less than 0.125 inches, less than 0.063, lessthan 0.032, less than 0.016, or less than 0.008 inches. According tocertain embodiments, the thickness is between 0.035 and 0.045 inches.According to certain embodiments, the thickness is greater than 0.03inches, greater than 0.1 inches, greater than 0.25 inches, greater than0.5 inches, or greater than 1 inch. According to some embodiments, thethickness may be scaled with frequency (for example, the distance may bea function of the wavelength of the highest designed frequency). Forexample, according to some embodiments, the thickness can be less than0.2λ, less than 0.1λ, less than 0.05λ, or less than 0.01λ. According tosome embodiments, the thickness can be greater than 0.005λ, greater than0.01λ, greater than 0.05λ, or greater than 0.1λ.

According to other embodiments, a radiating element ear includes twolobes, four lobes, five lobes, or more. According to certainembodiments, instead of lobes, the radiating element ear includescomb-shaped teeth, saw-tooth shaped lobes, blocky lobes, or a regularwave pattern. According to some embodiments, ears of radiating elementshave other shapes, for example they may be splines, or straight lines.Straight line designs may be desirable if the antenna array is designedto operate only at a single frequency, if for example, the frequencyspectrum is polluted at other frequencies. As appreciated by one ofordinary skill in the art, various techniques can be used to simulatethe impedance transformation of radiating elements in order to tailorthe shapes of the inner-facing irregular surfaces to the impedancetransformation requirements for a given phased array antenna design.

In addition to impedance matching, the shape of the inner-facingsurfaces of the comb portions can affect the operational frequencyrange. Other design considerations may also affect the frequency range.For example, the shape of the capacitive coupling portion 590 and themanner in which it forms a capacitive interface with the adjoiningclustered pillar can affect the frequency range. According to certainembodiments, for example, an antenna array according to certainembodiments, without a clustered pillar may have a lower frequencythreshold of 5 GHz and the same array with the clustered pillar may havea lower frequency threshold of 2 GHz.

According to certain embodiments, a radiating element 510 can bedesigned with certain dimensions to operate in a radio frequency bandfrom 3 to 22 GHz. For example, radiating element 510 may be between 0.5inches and 0.3 inches tall (preferably between 0.45 inches and 0.35inches tall) from the top of base plate 514 to the top of radiatingelement 510. According to some embodiments, the height of the radiatingelements may be scaled with frequency (for example, the height may be afunction of the wavelength of the highest designed frequency). Forexample, according to some embodiments, the height can be less than2.0λ, less than 1.0λ, less than 0.75λ, less than 0.5λ, or less than0.25λ. According to some embodiments, the height can be greater than0.1λ, greater than 0.2λ, greater than 0.5λ, or greater than 1.0λ.

Stem portions 570 and 572 may be between than 0.5 inches and 0.1 inchestall and preferably between 0.2 inches and 0.25 inches tall. Stemportions 570 and 572 may be scaled by the radiating element height. Forexample, the height of the stem portions may be equal to or less than ¾of the element height, equal to or less than ⅔ the element height, equalto or less than ½ the element height, or equal to or less than ¼ of theelement height. According to some embodiments, comb portions 580constitute the remainder of the element height. According to someembodiments, comb portions 580 may be between 0.1 and 0.3 inches talland preferably between 0.15 and 0.2 inches tall. According to certainembodiments, the distance from the outer edge of the capacitive couplingportion 590 of signal ear 516 to the outer edge of the capacitivecoupling portion 590 of ground ear 518 may be between 0.15 inches and0.30 inches and preferably between 0.2 and 0.25 inches. According tocertain embodiments, these values are scaled up or down for a desiredfrequency bandwidth. For example, arrays designed for lower frequenciesare scaled up (larger dimensions) and arrays designed for higherfrequencies are scaled down (smaller dimensions).

Relaxed Lattice Spacing

As discussed above with respect to FIGS. 2A-C and FIGS. 3A-C, thecapacitive coupling between a ground ear and a clustered pillar can havean impact on the spacing of radiating elements in the phased array. Thecapacitive coupling between a radiating element (such as a signal ear orground ear) and a clustered pillar can be used to improve the impedancematching of the antenna. As discussed above, the capacitive couplingbetween a clustered pillar and a radiating element can be a function ofthe surface overlap of the pillar and radiating element, as well as thewidth of the gap between the pillar and radiating element. Thus, bychanging the shape of the clustered pillar or the shape of the radiatingelement, the capacitive coupling can be increased or decreased.

As discussed above, the impedance matching of the antenna has asubstantial effect on the performance of the antenna. Thus, if the shapeof the radiating element or the clustered pillar is changed so as toincrease the surface overlap between the radiating element and theclustered pillar (i.e., increase the coupling between the two elements),the gap between the elements can be increased in order to maintain theimpedance matching. By increasing the gap between the elements, lesselements can be used in the array, while maintaining performance.

FIG. 9 illustrates a unit cell in which the components are shaped so asto provide increased coupling between a clustered pillar and theradiating element according to examples of the disclosure. In theexample of FIG. 9, phased array 900 can include a plurality of unitcells 902. Each unit cell 902 can include a clustered pillar 904 a-b, asignal ear 906, a ground ear 908, and a base plate 910. It should beunderstood that illustrations of unit cell 902 illustrated in FIG. 9truncate clustered pillars 904 a-b for illustrative purposes only. Inthe example of FIG. 9, the phased array is shown in a single poleconfiguration, meaning the antenna is configured to receive signals in asingle polarization. A phased array that receives in a singlepolarization can be useful in scenarios in which the targets ofinterests are transmitting along one coordinate plane such as thehorizon, thus only requiring the azimuth to be scanned by the phasedarray.

The components of the unit cell 902 (i.e., the base plate 910, theground clustered pillars 9 a-b, the signal ear 906 and the ground ear908) can be manufactured from the same materials, and operate insubstantially the same ways as discussed above with respect to the phasearray antennas of FIGS. 2A-C and FIGS. 3A-C. A difference (as furtherdiscussed below) between the phased array antenna of FIGS. 2A-C, FIGS.3A-C, and the antenna of FIG. 9 is the shape of the clustered pillars904 a-b, the shape of signal ear 906, and the shape of the ground ear908.

FIGS. 10A-C illustrate an isometric, side, and top view of a unit cellof a phased array according to examples of the disclosure. As discussedwith respect to FIG. 9, the unit cell 1000 illustrated in FIGS. 10A-C,can represent a single-pole configuration wherein the unit cells can bearranged on a lattice of the phased array in a first polarization axis(i.e., either horizontally or vertically polarized). Like the example ofFIG. 9, unit cell 1000 can include a base plate 1010, clustered pillars1004 a-b, ground ear 1008, and signal ear 1006. Also illustrated in thefigure is plug 1012. As discussed in further detail below, the signalear 1006 can be overmolded into plug 1012 and then then inserted intobase plate 1010.

Turning to FIG. 10C (i.e., the top view of unit cell 1000), the shape ofthe signal ear 1006 and the ground ear 1008 can be best viewed. Asillustrated in FIG. 10C, ground ear 1008 can include an overlappingportion 1014 whose surface area is oriented to face clustered pillar1004 a. The surface area of overlapping portion 1014 can be orientedwith respect to clustered pillar 1004 a, so as to “wrap around” theclustered pillar 1004 a. In other words, the overlapping portion 1014can be configured to maximize the surface area of the ground ear 1008that is facing the clustered pillar 1004 a. By orienting the overlappingportion 1014 in this manner, the amount of capacitive coupling betweenclustered pillar 1004 a and ground ear 1008 can be maximized.

Signal ear 1006 can also include an overlapping portion 1016 that can beoriented with respect to clustered pillar 1004 b so as to “wrap around”the clustered pillar 1004 b. In this way, the surface area of the signalear 1006 that is facing the clustered pillar 1004 b can be maximizedthereby maximizing the capacitive coupling between the clustered pillar1004 b and the signal ear 1006.

FIG. 11 illustrates a comparison between the top view of the unit celldescribed with respect to FIGS. 3A-C, and the top view of the unit celldescribed with respect to FIGS. 10A-C. As discussed in detail above,with respect to FIGS. 3A-C, unit cell 1100 can include a base plate1112, a plurality of signal ears 1114 a-b, a plurality of ground ears1116 a-b, and a ground clustered pillar 1120. Also as discussed indetail above, the unit cell 1100 is configured to operate as a dual polephased array (i.e., the antenna is scanned in two orthogonal coordinateplanes). Unit cell 1102 can include a base plate 1110, a signal ear1106, a ground ear 1114, and a ground clustered pillar 1120.Furthermore, as discussed in detail above, the unit cell 1102 isconfigured to operate as a single pole phased array (i.e., the antennais scanned along a single coordinate plane).

In comparing unit cell 1100 and unit cell 1102, the differences betweenthe shapes of the ground clustered pillars 1120 and 1104 a-b can bereadily apparent. For example, whereas ground clustered pillar 1120 iscross-shaped to allow for the coupling of elements oriented in twoorthogonal positions, the ground clustered pillars 1104 a-b arecylindrically shaped. Furthermore, the signal ears 1114 a-b of unit cell1100 and signal ears 1106 can be shaped differently. With respect tounit cell 1100, the signal ears 1114 a-b are shaped to create aninterdigitated capacitance between each signal ear and one arm of thecross-shaped ground clustered pillar 1120. Specifically, the signal ears1114 a-b, contain overlapping portions 1118 a-b respectively, that areshaped to conform to the shape of the ground clustered pillar 1120,thereby maximizing the surface area of the signal ear that is directlyfacing the ground clustered pillar.

In comparison, unit cell 1102 includes a signal ear 1106 withoverlapping portion 1116 that can be shaped to maximize the surface areathat is overlapping (i.e., “wrapping around”) the ground clusteredpillar 1104 a as discussed in detail above. The difference in the shapebetween ground clustered pillar 1120 and ground clustered pillars 1104a-b as well as the difference in the signal ears 1114 a-b and signal ear1106 can mean that the capacitive coupling between signal ear 1106 andground clustered pillar 1104 b can be greater than the capacitivecoupling between ground clustered pillar 1120 and signal ears 1114 a-b(assuming the gap between the signal ears and the ground clusteredpillars are the same).

Since the capacitive coupling is greater for unit cell 1102 as comparedto 1100, in order to maintain impedance matching (as discussed above),the gap between the overlapping portion 1116 of signal ear 1106 and theground clustered pillar 1104 b can be increased. This in turn can meanthat each unit cell 1102 in a phased array can be further apart from oneanother. As an example whereas a phased array utilizing a unit cell 1100may have adjacent unit cells spaced λ/2×λ/2 apart from one another(wherein λ, is equal to the maximum wavelength of the desired bandwidth)thereby requiring a 16×16 element array with an aperture of4.75″×4.75″×0.5″, a phased array utilizing a unit cell 1102 may haveadjacent unit cells spaced λ/2×0.9λ, apart from one another therebyrequiring only a 16×8 element array.

The benefits of a phased array design that can maintain aperture sizeand bandwidth capabilities with fewer unit cells are readily apparent.Fewer elements can lower the overall weight of the phased array, whilealso lowering power requirements and the overall footprint of the phasedarray.

Overmolding of Radiating Elements

Mechanical failures can be problematic for a phased array antenna, sinceoften times a phased array antenna can be subjected to high vibrationenvironments that can potentially cause adjacent radiating elements tocontact the ground clustered pillars or to cause connections betweenparts of a unit cell to break off or become damaged.

Referring to the example of FIG. 4, and as discussed above, signal ear416 and ground ear 418 can be assembled to plug 428. Plug 428 may beformed of a dielectric material, such as plastic, in order to maintainthe electrical isolation of signal ear 416 from ground ear 418 and baseplate 414. As further discussed above, signal ear 416 and ground ear 418can be inserted into receptacles in plug 428. In some embodiments, plug428 can be molded around signal ear 416 and ground ear 418 in a processcalled overmolding. Both the signal and ground ears can be overmoldedand then inserted into the phased arrays base plate 414.

While overmolding the signal ear and ground ear in the manner describedabove can lead to more efficient manufacturing of the unit cell,overmolding can also introduce a source of potential mechanical failuredue to the vibration environment of phased arrays described above. Thesignal ear and ground ear, by being overmolded can suffer mechanicalfailure during vibration of the unit cell in the phased array.Furthermore, and as discussed below in detail, when both the signal earand the ground ear are overmolded, in some embodiments, the ground earcan be press fit to make the required contact with the base plate of thearray. Utilizing a press fit to ensure electrical connection between theground ear and the base plate can lead to an increased risk ofelectrical discontinuity between the two components.

Recognizing that the ground ear needs to be connected to the ground,while the signal ear is to be isolated from the ground, instead ofovermolding both the ground ear and the signal ear, if one or more ofthe radiating elements can be directly connected to elements with thebase plate 414, the risk of mechanical and electrical failure of thearray can be decreased.

FIGS. 12A-B illustrate a phased array in which the pillars and groundsears of the radiating elements are integrated into the base plate, andthe signal ear is overmolded according to examples of the disclosure.Turning to FIG. 12a , the unit cell 1200 can include the same componentsas described above with respect to FIGS. 2A-C. Unit cell 1200 caninclude base plate 1204, ground clustered pillar 1202 a-b, ground ear1210, and signal ear 1206. These components can operate in substantiallythe same way as their counterparts described with respects to FIGS.2A-C. As shown in the example of FIG. 12, the signal ear 1206 can beovermolded and fit into plug 1208. Plug 1208, with the signal ear 1206inserted into it, can be plugged into the base plate 1204. Ground ear1210 can be directly connected to the base plate 1204. In contrast tothe example described with respect to FIGS. 4a-b , wherein both thesignal ear 416 and the ground ear 418 are overmolded into plug 428, inthe example of FIGS. 12a-b , only the signal ear 1206 may be overmoldedinto plug 1208, while ground ear 1210 can be connected directly to thebase plate 1204.

In this way, the ground ear 1210 can be directly connected to ground(since as described above the base plate 1204 is grounded), while thesignal ear 1206 can be electrically isolated from the base platecomponents via the plug 1208. The signal ear 1206 can be electricallyisolated from the base plate 1204 via the plug 1208, because just as theplug 428 in the example of FIGS. 4a-b , the plug 1208 may be formed of adielectric material, such as plastic, in order to maintain theelectrical isolation of signal ear 1206 from ground ear 1210 and baseplate 1204. Plug 1208 may be formed from various plastics such as ABS,Nylon, PA, PBT, PC, PEEK, PEK, PET, Polyimides, POM, PPS, PPO, PSU, orUHMWPE. In some embodiments the plug 1208 can be formed forpolyethermide (PEI), a high-performance, high-temperature plastic, thatcan achieve the required impedance matching to maintain the performanceof the phased array. FIG. 12a illustrates the unit cell 1200 with thesignal ear 1206 and plug 1208 detached from the unit cell. FIG. 12billustrates the same unit cell with the plug 1208 “plugged in” to thebase plate 1204.

The ground ear 1210 can be integrated into the base plate 1204 byutilizing a two-step machining process according to examples of thedisclosure. The first step can include utilizing computer numericalcontrol (CNC) milling to remove material from an aluminum piece so as toform the base plate and ground ear out of a single block of metal. Thesecond step can include utilizing wire electrical discharge machining(wire EDM) to finely carve out the remaining ground ear features thatare too fine to be carved out by the milling process.

By overmolding only the signal ear 1206, and connecting the ground ear1210 directly to the base plate 1204, the number of locations forpossible mechanical failure (e.g., electrical discontinuity) can bereduced since fewer components are susceptible to the mechanical risksassociated with attaching components via overmolding.

Flexible Connectors

While reducing the number of components of a unit that are inserted intothe base plate via overmolding can reduce the risk of mechanical failureduring the operation or deployments of a phased array antenna, theconnections between the unit cells of the phased array and anydownstream electronics can present a risk of mechanical failure,especially in a high vibration environment.

FIG. 13 illustrates an exemplary feeding structure of the radiatingelement in the base plate of the phased array configured to be matedwith a coaxial connector according to examples of the disclosure.

FIG. 13 illustrates a cross-section of a unit cell 1300 wherein theconnection between a signal ear 1306 and a SMA connector 1308 isvisible. Similar to the examples discussed above, signal ear 1304 can beconnected to the unit cell 1300 via plug 1312 and provide anelectrically isolated path for the signal ear 1306 to make electricalcontact with SMA connector 1308. SMA connector 1308 can include aconductive portion 1310 that when contacted by signal ear 1304 canprovide a closed electrical connection between the signal ear and anydownstream electronics connected to the co-axial cable associated withthe SMA connector.

While the connection between the signal ear 1304 and the SMA connector1308 can generally be maintained during normal operation of the phasedarray, the antenna array may be subject to vibration as described above.During vibration the connection between SMA connector 1308 and signalear 1304 may become loose or may become disconnected entirely therebynegatively impacting the performance of the phased array. Since thesignal ear 1304 and the conductive portion 1310 of SMA connector 1308are both made of rigid metal material, they can be especiallysusceptible to an interruption of connection caused by vibration.

Since rigid connections between conductive elements may be susceptibleto mechanical failure especially in environments that experiencevibration such as the environment that a phased array may operate or bedeployed, flexible connectors may provide improved reliability andreduce the risk of mechanical failure of the connection. For example,flexible connectors can dampen vibration, which in turn can improve theoverall mechanical reliability of electrical connections in the phasedarray.

Thus, rather than relying on direct contact between the rigid bodies ofthe signal ear 1304 and the conductive portion 1310 of SMA connector1308, an intervening flexible connector may provide a more reliablesolution that is less prone to mechanical failure.

As an example, rather than directly connecting the signal ear 1304 withSMA connector 1308, an intervening flexible connector that can withstanda vibration environment can be employed to reduce the risk of mechanicalfailure of the connection in a vibration environment.

A Zebra® connector designed by Fujipoly is an example of an elastomericconnector that can be employed to reduce the risk of mechanical failure.A Zebra connector can include alternating and insulating regions in arubber or elastomer matrix that can be configured to produce overallanisotropic conductive properties. Because of their flexibility, Zebraconnectors can create a gasket-like seal between rigid connections andcan excel in shock and anti-vibration applications owing to theflexibility of the connector. The conductive material in a Zebraconnector can include carbon, silver, and gold.

FIGS. 14A-B illustrate an exemplary feeding structure of a radiatingelement in the base plate of the phased array configured to be matedwith an elastomeric gasket according to examples of the disclosure. FIG.14A illustrates an exemplary connection between a signal ear and aco-axial cable employing a SMA connector that employs an elastomericconnector according to examples of the disclosure. Similar to theexample of FIG. 13, in FIG. 14A, a unit cell 1400 can include a baseplate 1402, a signal ear 1406 that is overmolded into a plug 1404. Theplug 1404 can electrically isolate the signal ear 1406 from the baseplate 1402, and can allow the signal ear 1406 to extend down into thebase plate to make an electrical connection to SMA connector 1410. SMAconnector can include a conductive portion 1412. In contrast to theexample of FIG. 13, in the example of FIG. 14A, rather than directlyconnecting the signal ear 1406 to the conductive portion 1412 of the SMAconnector 1410, an elastomeric conductor 1408 can be inserted betweenthe signal ear 1406 and SMA connector 1410. The elastomeric conductor1408, as described above, can provide a flexible conductive pathwaybetween the signal ear 1406 and the conductive portion 1412 of SMAconnector 1410.

FIG. 14B illustrates an exemplary connection between a signal ear and aprinted circuit board (PCB) that employs an elastomeric connectoraccording to examples of the disclosure. As illustrated in FIG. 14B, PCBconnections can allow for a high-density spacing of connections incontrast to RF connectors. The unit cell 1414 of FIG. 14B can includethe same components as the example of FIG. 14A including a base plate1416, plug 1418, signal ear 1420 and an elastomeric connector 1422 thatall are configured to operate identically to their counterpartsdiscussed above. In the example of FIG. 14B, rather than connecting to aco-axial cable, the signal ear can be connected to a PCB circuit 1424that can include a connector 1426. Connector 1426 can make electricalcontact with elastomeric connector 1422, which can then complete anelectrical path between the signal ear 1420 and the PCB circuit 1424.

FIG. 15 illustrates a plurality of unit cells with a common elastomericconnector according to examples of the disclosure. FIG. 15 illustrates aview underneath one unit cell 1502, and a view from underneath aplurality of unit cells 1504. As shown in the figure, a elastomericconnector strip can be disposed underneath the unit cell 1502 such thatit can make contact with the stem of signal ear 1506 that can protrudeunderneath plug 1508. Turning to the plurality of unit cells 1504, anelastomeric strip 1510 can be disposed underneath the plurality of unitcells 1504 such that the elastomeric strip can make contact with aplurality of signal ear holes 1512 a-h. Each signal ear hole 1512 a-hcan receive a signal ear (inserted into a plug) such that when thesignal ear is plugged into the hole 1512, the stem of the signal ear canmake contact with elastomeric strip 1510.

In additional embodiments of the disclosure, instead of employing anelastomeric connector, the unit cell can employ a RF interposer such asa Fuzz Button® connector that can connect an SMA connector or PCBcircuit Board. Fuzz Buttons® are compressible contact pins made up ofhighly specialized very fine wire that can be wound up into a cylinderof customizable size. A Fuzz Button® connector, in which the conductiveelement that conducts a signal between two electrical connections, canemploy a spring-like connector that can withstand a high-vibrationenvironment while minimizing the risk of mechanical failure in much thesame way as an elastomeric connector can. Fuzz Buttons ® can be employedto make contacts for the phased array due to the Fuzz Buttons' smallsize (the small size allows them to fit in available spacing). They areflexible connectors that can ensure a good electrical connection, whileremaining versatile enough to be used with either an SMA or PCBconnector. Because they are highly conductive, they can preserve signalintegrity. Furthermore Fuzz Buttons® have been verified to operate atthe operational frequencies used by the phased array and detailed above.

FIG. 16A illustrates an exemplary connection between a signal ear and aco-axial cable employing a SMA connector that employs a Fuzz Button® RFinterposer according to examples of the disclosure. Similar to theexample of FIG. 13, in FIG. 16A, a unit cell 1600 can include a baseplate 1602, a signal ear 1606 that is overmolded into a plug 1604. Theplug 1604 can electrically isolate the signal ear 1606 from the baseplate 1602, and can allow the signal ear to extend down into the baseplate 1602 to make an electrical connection to SMA connector 1610. SMAconnector 1610 can include a conductive portion 1612. In contrast to theexample of FIG. 15, in the example of FIG. 16A, rather than directlyconnecting the signal ear 1606 to the conductive portion 1612 of the SMAconnector 1610, a Fuzz Button® connector 1608 can be inserted betweenthe signal ear 1606 and SMA connector 1610. The Fuzz Button® connector1608, as described above can provide a flexible conductive pathwaybetween the signal ear 1606 and the conductive portion 1612 of SMAconnector 1610.

FIG. 16B illustrates an exemplary connection between a signal ear and aprinted circuit board (PCB) that employs a Fuzz Button® connectoraccording to examples of the disclosure. The unit cell 1614 of FIG. 16Bcan include the same components as the example of FIG. 16A including abase plate 1616, plug 1618, signal ear 1620 and an Fuzz Button®connector 1622 that all are configured to operate identically to theircounterparts discussed above. In the example of FIG. 14B, rather thanconnecting to a co-axial cable, the signal ear can be connected to a PCBcircuit 1624 that can include a Fuzz Button® connector 1626. FuzzButton® connector 1626 can make electrical contact with Fuzz Button®connector 1622, which can then complete an electrical path between thesignal ear 1620 and the PCB circuit 1624.

All Metal Design

While the phased array antenna embodiments described above can receive awide-bandwidth low-profile signal, they may present manufacturingchallenges that can make the process of producing and assembling thearray challenging. As an example, with respect to the phased arraydiscussed above with respect to FIGS. 9-16, the process of manufacturingsuch an array can involve machining various components separately andthen assembling the components to produce a unit cell of the phasedarray.

Referring back to FIG. 4, signal ear 416 and ground ear 418 can beassembled into plug 428, which as described above can be formed of adielectric material such as plastic in order to maintain the isolationof signal ear 416 from ground ear 418 and base plate 414. Also asdescribed with respect to FIG. 4, plug 428 can be molded around signalear 416 and ground ear 418 in a process called overmolding. While such aconfiguration can lead to a more efficient manufacturing of the unitcell, nonetheless the process can require that the signal ear, groundear, base plate, and plug be manufactured separately and then assembledtogether to generate a unit cell of the phased array. The process cantherefore require a more complex and time consuming manufacturingprocess because the components are separately manufactured and thenassembled.

However, a unit cell in which the base plate, signal ear, and ground earcan be created from a single piece of conductive material (i.e., metal)could lead to a manufacturing process that requires less complexity andrequires minimal assembly. Using the example of metal, a phased arrayconfiguration that can allow for the base plate, ground ear and signalear to be created from a single piece of metal can be produced byadditive manufacturing techniques that can reduce the complexity andtime required to engage in the manufacturing process.

Additive manufacturing can refer to processes in which a common materialis joined or solidified under computer control to create an object, withmaterial being added together is a specific way to create the object. Byconfiguring the base plate, signal ear, and ground ear to bemanufactured in one piece using a common material, the entire unit cellof a phased array can be manufactured in a single process rather thanhaving to be manufactured as separate components. Such a process canreduce the time and complexity required to manufacture a phased arraywhich can include hundreds or thousands of unit cells.

FIG. 17A-B illustrates a phased array and corresponding unit cell inwhich the components are formed from a single material so as utilize anadditive manufacturing process according to examples of the disclosure.Referring to FIG. 17A, the phased array can include a unit cell 1700that includes a ground ear 1702, a signal ear 1704, and a base plate1716 that are configured to operate in substantially the same manner asdescribed above with respect to their counterparts described withrespect to FIGS. 9-16. However, rather than being configured such thateach individual component is required to be separately manufactured, theunit cell 1700 can be configured such that the signal ear 1704, groundear 1702, and base plate 1716 can be manufactured as a single continuousobject from a common material such as metal.

In the example of FIG. 17A, the ground ear 1702 can include two supportposts 1706 and 1708 that are integrated directly into the base plate1716. In other words the base plate 1716 and the ground ear 1702 can befabricated from a common metal piece and are connected to one another byvirtue of the contact between posts 1706 and 1708 of the ground ear1702. As described above, the base plate 1716 can be electricallygrounded, and as posts 1706 and 1708 of the ground ear 1702 areintegrated directly into the base plate, they too are provided with apath to ground.

The signal ear 1704, in order to be symmetric to the ground ear 1702,can also include two support posts 1710 and 1712. Similar to ground ear1702, support post 1710 can be directly integrated into base plate 1716thereby providing a direct path to ground for the signal ear 1704.However, if post 1712 were also to be directly integrated into the baseplate 1716 (similar to post 1708), then the signal ear 1704 would becompletely shorted to ground thereby rendering the signal ear inoperableto act as a receiving or transmitting element in a phased array antenna.Therefore as discussed in further detail below, post 1712 can beinserted into an airgap 1714 that can be intentionally created withinbase plate 1716 so as to avoid grounding the signal ear 1704. The airgapcan be shaped in the manufacturing process so as to match the impedanceof the signal ear thereby ensuring minimum impacts from signalreflection during operation of the phased array. By inserting the post1712 into an airgap 1714, the unit cell 1700 may no longer require anyovermolding of the post 1712 to avoid grounding the post, since theairgap can be of sufficient dimeter to ensure that during operation ofthe phased array antenna the post 1712 does not make contact with thebase plate 1716. Because the signal ear 1704 includes a post 1712 thatcan be inserted into an airgap 1714 of the base plate 1716, the otherpost 1710 can provide mechanical support to the signal ear 1704 toensure that it remains attached to the phased array during operation. Asshown in the figure, the shape of the signal ear 1702 and the ground ear1704 can be specifically configured to optimize the input impedance ofthe antenna.

The unit cell 1700 can also include one or more clustered pillars 1718,similar to the example unit cells discussed above. Discussed in furtherdetail below, the clustered pillars 1718 can be shaped with respect tothe signal ear 1704 and ground ear 1702 so as to control the capacitivecoupling between adjacent elements in the phased array, thereby allowingfor good impedance matching at the lower-frequency end of the bandwidth,and thereby effectively increasing the operational bandwidth of the unitcell 1700. FIG. 17B illustrates a phased array antenna that utilizes theunit cell of FIG. 17A. The phased array 1720 can include a plurality ofunit cells 1700 to form a full array.

FIG. 18A illustrates a side view of an exemplary all-metal unit cell ofa phased array antenna according to examples of the disclosure. Theside-view illustrated in FIG. 18A corresponds to the unit cell describedwith respect to FIG. 17A. In the view of FIG. 18A, it can be seen thatthe signal ear 1804 and the ground ear 1802 are symmetric with respectto one another. The signal ear 1804 includes posts 1810 and 1812, whileground ear 1802 includes posts 1806 and 1808. As discussed above, posts1806, 1808, and 1810 can be integrated with the base plate 1816directly, while post 1812 can be inserted into an airgap created in thebase plate 1816.

As in FIG. 18, the unit cell 1800 can also include clustered pillars1818 a and 1818 b. The clustered pillars 1818 a and 1818 b can beconfigured to maximize the electromagnetic coupling between adjacentunit cells thereby improving the performance of the phased arrayoverall. As discussed further below, the signal ear 1804 and the groundear 1802 can also be shaped to present the maximum surface area forinteracting with the clustered pillars 1818 a and 1818 b.

The side view presented in FIG. 18A illustrates the symmetry between thesignal ear 1804 and ground ear 1802. The symmetry between the twocomponents can make it easier to tile the phased array (i.e., tile theunit cell on a common base plate 1816) during the manufacturing process,thereby reducing the complexity of the manufacturing process.

FIG. 18B illustrates a top view of an exemplary all-metal unit cell of aphase array antenna according to examples of the disclosure. The topview presented in FIG. 18B can correspond to the unit cell described inboth FIGS. 17A and 18A. The top view of FIG. 18B more clearlyillustrates the airgap 1814 that is configured to accept post 1812 ofsignal ear 1804. As discussed above with respect to FIG. 17, the airgap1814 can be intentionally created within base plate 1816, so that it canreceive post 1812 of signal ear 1804 without allowing the post to makecontact with the base plate. In contrast to post 1810 of signal ear 1804which is directly integrated and makes contact with the grounded baseplate 1816, the post 1812 can be directly connected to an interface,such as a coaxial cable or PCB interface (discussed in further detailbelow), without making contact with the base plate 1816. The airgap 1814can facilitate this configuration by ensuring that the clearance betweenthe signal ear post 1812 and the base plate 1816 is sufficient to ensurethat the signal post 1812 will not make contact with the base plate 1816and will only make contact with the interface to a connector asdescribed in further detail below.

The size of the airgap 1814 can be large enough to ensure that the post1812 does not inadvertently make contact with the base plate duringoperation of the phased array antenna. If the diameter of the airgap istoo small, then during operation of the phased array antenna, the signalear post 1812 embedded into the airgap 1814 may vibrate and makeintermittent contact with the base plate 1816 thus intermittentlygrounding the signal ear 1804 and thereby degrading the performance ofthe antenna. However, the size of the airgap 1814 can be furtherconstrained by the ground ear 1802, and more specifically by the post1808 of the ground ear. If the diameter of the airgap is too large, thenthe airgap may overlap with the area on the base plate that is supposedto be integrated with post 1808 thereby degrading the connection betweenthe ground ear 1802 and the base plate 1816.

The diameter of the airgap 1814 can also be influenced by the impedanceof the signal ear post 1812. In order to achieve suitable impedancematching between the base plate 1816 and the signal ear post 1812, thediameter of the airgap 1814 can be controlled to ensure that animpedance mismatch does not occur. As the impedance of the signal earpost 1812 is proportional to the diameter of the post itself, the ratioof the diameter of the signal post to the diameter of the airgap 1814can be controlled so as to achieve suitable impedance matching.

In addition to more clearly illustrating the airgap 1814, the top viewillustrated in FIG. 18B can also more clearly illustrate the geometricrelationship between the clustered pillars 1818 a and 1818 b, and thesignal ear 1802 and ground ear 1804. In the example of FIG. 18B, theclustered pillars 1818 a and 1818 b are shown as comprising two separatetriangular portions. In such a configuration, the signal ear 1804 andground ear 1802 can be include a triangle end portion 1820 and 1822respectively. The triangle portions 1820 and 1822 and signal ear 1804and ground ear 1802 can be shaped this way, so as to maximize thesurface area of the signal ear and ground ear that is directly facingthe clustered pillars 1818 a and 1818 b. By maximizing the surface area,the amount of capacitive coupling between the pillars can be controlled,thereby broadening the array's operational bandwidth. As describedabove, the shape of the ground ear 1802 and the signal ear 1804(i.e.,the portions that face the other ear) can be shaped so as to optimizethe input impedance of the antenna.

In the example of FIGS. 17 and 18A-B the unit cell of the phased arrayantenna is shown as having triangular shaped clustered pillars and thesignal and ground ears are shown having have triangular shaped ends soas to control the capacitive coupling between the clustered pillars andthe radiating elements. The shape of the clustered pillars can bedependent on numerous factors. In the example of FIGS. 17 and 18A-B, theshape of the clustered pillars can be triangular (in contrast to thestar-like shape shown in FIGS. 9-16) due to the changes in theconfiguration of the unit cell engendered by the all-metallic design.

Referring back to FIG. 18A, the fact that signal ear 1804 includes ametallic support post 1810 that is directly integrated into the baseplate 1816 can create a need to change the shape of the clustered pillar1818. Specifically, because the support post 1810 provides a direct pathto ground via the base plate 1816, the bandwidth of the phased arraythat utilizes a plurality of unit cells 1800 may be negatively impacted.To account for this drop in bandwidth caused by the all-metal design,the shape of the clustered pillar 1818 can be altered so as to improvethe capacitive coupling between the elements, thereby compensating forloss in bandwidth caused by the support post's 1810 contact with thebase plate.

Though the all-metal design examples of FIGS. 17-18 illustratetriangular clustered pillars, the disclosure should not be seen aslimiting and the clustered pillars can take on various shapes. Asdescribed above with respect to FIGS. 9-16, the clustered pillar wasconfigured in a star shape, and the ends of the radiating elements wereshaped accordingly to control the capacitive coupling between theelements in the array. In one or more examples of the disclosure, theunit cell of a phased array that utilizes an all-metal design can stillutilize the same clustered pillars and radiating element shapesdescribed above with respect to FIGS. 9-16.

FIGS. 19A-C illustrate exemplary pillar configurations for a phasedarray antenna with all-metal unit cells according to examples of thedisclosure. The example of FIG. 19A illustrates two separate halves oftwo separate unit cells. In the example of FIG. 19A, the electricalinteraction between the signal ear 1902 of a first unit cell and theground ear 1904 of a second unit cell is illustrated. As shown in thefigure a “star-shaped” clustered pillar 1906 is disposed between theground ear 1904 and the signal ear 1902. Also as illustrated in thefigure, the shape of the end of the signal ear 1902 facing the pillar isconfigured to maximize the surface area of the signal ear exposed to theclustered pillar 1906. Similarly, the shape of the end of the ground ear1904 is configured to maximize the surface area of the ground earexposed to the clustered pillar 1906.

The phased array elements illustrated in FIG. 19A can be implementedusing the all-metal design described above. As shown in the figure, theground ear 1904 includes two metal posts that are directly integratedinto the base plate 1908. The signal ear 1902 is shown as having twometal posts, with one post (i.e., the support post) being directlyintegrated into the base plate 1908, and with the other metal post beinginserted into the base plate via an airgap as described above withrespect to FIGS. 17-18.

FIG. 19B illustrates an exemplary phased array with a triangularclustered pillar according to examples of the disclosure. The example ofFIG. 19B can include the same configuration of clustered pillars andradiating elements as discussed with respect to FIG. 18. In the exampleof FIG. 19B, the electrical interaction between the signal ear 1910 of afirst unit cell and the ground ear 1912 of a second unit cell isillustrated. As shown in the figure a plurality of “triangle shaped”clustered pillars 1914 a and 1914 b are disposed between the ground ear1912 and the signal ear 1910. The clustered pillars 1914 a and 1914 bcan be disjointed meaning they can be disposed in the base plate 1916 astwo separate pieces that are separately integrated with the base plate.Also as illustrated in the figure, the shape of the end of the signalear 1910 facing the clustered pillars194 a-b is configured to maximizethe surface area of the signal ear exposed to the clustered pillars.Similarly, the shape of the end of the ground ear 1912 is configured tomaximize the surface area of the ground ear exposed to the clusteredpillars 1914 a-b.

The phased array elements illustrated in FIG. 19A can be implementedusing the all-metal design described above. As shown in the figure, theground ear 1912 includes two metal posts that are directly integratedinto the base plate 1916. The signal ear 1912 is shown as having twometal posts, with one post (i.e., the support post) being directlyintegrated into the base plate 1916, and with the other metal post beinginserted into the base plate via an airgap as described above withrespect to FIGS. 17-18.

In one or more examples, the all-metal design described above can beimplemented using a configuration that does not include any clusteredpillars. Such a configuration can make manufacturing even less complexby not requiring the fabrication of a clustered pillar which can maketiling the phase array (i.e., assembling multiple unit cells onto acommon base plate) less complex. Furthermore, a design that does notinclude a clustered pillar between unit cells can decrease the overallweight of the design because it may not require as much material tofabricate a unit cell.

FIG. 19C illustrates an all-metal phased array unit cell configurationwithout a clustered pillar according to examples of the disclosure. Inthe example of FIG. 19C, a signal ear 1918 of a first unit cell can bedisposed adjacent to a ground ear 1920 of a second unit cell. The shapesof the signal ear 1918 and the ground ear 1920 can be configured tomaximize the surface area of interaction between them. In other words,the shape of the signal ear 1918 can be configured so that the portionof the signal ear that is facing the ground ear 1920 can have themaximum surface area of exposure to the ground ear. Likewise, the shapeof the ground ear 1920 can be configured so that the portion of theground ear that is facing signal ear 1918 can have the maximum surfacearea of the exposure to the signal ear.

The “pillar-less” design illustrated in FIG. 19C can cause the phasedarray antenna to have less bandwidth capability, however as discussedabove, the manufacturing complexity and weight of the overall phasedarray can be decreased as a result of removing the clustered pillar fromeach unit cell.

FIG. 20 illustrates an isometric view of a phased array antenna withall-metal unit cells and a “pillar-less” configuration according toexamples of the disclosure. In the example of FIG. 20, a two unit cells2002 and 2004 are oriented perpendicularly with respect to one another.Unit cell 2002 includes a signal ear 2006 and a ground ear 2008. Unitcell 2004 can be oriented perpendicularly to unit cell 2002 and caninclude a signal ear 2010 and a ground ear 2012. As the unit cells 2002and 2004 are perpendicularly oriented with respect to one another, thesignal ear 2006 of unit cell 2002 can be perpendicularly oriented andadjacent to the signal ear 2010 of unit cell 2004. Furthermore, theperpendicular orientation between unit cells can allow the phased arrayto be configured as a dual-polarization phased array meaning the phasedarray can send and receive signals in orthogonal polarizations (i.e,RHCP, LHCP, Vertical, Horizontal, etc.)

As illustrated in the figure, the phased array can be implementedwithout requiring any clustered pillars. In order to facilitate thisconfiguration, the signal ears of each unit cell can be shaped so as toprovide an optimal level of capacitive coupling between adjacent andperpendicular signal ears. In the example of FIG. 20, each signal earincludes a triangular shaped end piece that is shaped so as to providethe maximum amount of surface for capacitive coupling to its adjacentand perpendicular signal ear. Thus in the example of FIG. 20, signal ear2006 can have a triangular end piece that is shaped so as to present anoptimal amount of surface area to signal ear 2010 that is also shapedwith an identical triangular end piece.

In the example of FIG. 20, each signal ear 2006 and 2010 can be shapedso as to optimize capacitive coupling with the two signal ears that areperpendicular to its position. For instance in the example of FIG. 20,signal ear 2006 can have a triangular end piece such that one side ofthe triangle can be capacitively coupled to signal ear 2010 which isoriented perpendicular to signal ear 2006 and another side of thetriangle can be capacitively coupled to another signal ear (notpictured) that is also oriented perpendicularly to signal ear 2006.

In one or more examples, a phased array antenna may have an assortmentof different clustered pillar arrangements and signal ear shapes on thesame array. While such an arrangement may increase the manufacturingcomplexity of the phased array it can lead to various benefits includingspecific bandwidth capabilities that may be desirable.

FIG. 21 illustrates a side view of a phased array antenna with all metalunit cells and with a mixed clustered pillar arrangement according toexamples of the disclosure. The example of FIG. 21 illustrates 4separate unit cells 2102, 2104, 2106, and 2130 on a common base plate2108. Unit cell 2102 is illustrated as having a signal ear 2110 and aground ear 2112. Ground ear 2112 can be shaped to interface with aclustered pillar 2114. Clustered pillar 2114 can be “star-shaped” asshown in the figure. Ground ear 2112 can be shaped to interface with theclustered pillar 2114 as described above.

Unit cell 2104 can include a signal ear 2116 that is shaped to interfacewith clustered pillar 2114. Unit cell 2104 can also include a ground ear2118 that is shaped so as to not require a clustered pillar. As shown inthe example of FIG. 21, unit cells 2104 and 2106 can be configured sothat no clustered pillar is required to be disposed between them. Thus,the signal ear 2120 of unit cell 2106 can be shaped likewise so as tonot require a clustered pillar. Unit cell 2106 can also include a groundear 2122 that can be shaped to capacitively couple to a clustered pillar2124 that is star-shaped. Unit cell 2130 can therefore include a signalear 2126 that can also be shaped to capactively couple to clusteredpillar 2124. Finally, unit cell 2130 can also include a ground ear 2128.

Thus, in the example of FIG. 21, the phased array can include multiplepillar types or no pillar at all between unit cells. Because such anarrangement can include radiating elements of varying size and shapes,some of the radiating elements (i.e., the larger elements) may exhibitimproved band performance at lower frequency bands, while the smallerradiating elements may exhibit improved band performance at higherfrequency bands. In this way, the overall bandwidth of the phased arraymay be increased by including mixed types of radiating elements andclustered pillars.

Referring back to the example of FIGS. 18A and 18B, the base plate 1816can include an airgap 1814 that can accommodate a metallic post 1812belonging to signal ear 1804. As described above, signal ear 1804 can bemated to a coaxial cable or PCB connection via the metallic post 1812without making electrical contact with the base plate 1816 due to thecreation of the airgap 1814 within the base plate 1816.

FIG. 22 illustrates an exemplary RF interconnect with PCB or a coaxialcable for a phased array that utilizes an all-metal unit cell accordingto examples of the disclosure. In the example of FIG. 22 the connectionbetween a signal ear and a co-axial cable employing a SMA connector thatemploys an elastomeric connector is shown. In the example of FIG. 22, aunit cell 2200 can include a base plate 2202, a signal ear post 2206that is inserted into an airgap 2204 as described above. The airgap 2204can have a diameter large enough so as to electrically isolate thesignal ear post 2206 from the base plate 2202, and can allow the signalear to extend down into the base plate to make an electrical connectionto SMA connector 2210. SMA connector can include a conductive portion2212. In one or more examples, rather than directly connecting thesignal ear post 2206 to the conductive portion 2212 of the SMA connector2210, an elastomeric conductor 2208 can be inserted between the signalear post 2206 and SMA connector 2210. The elastomeric conductor 2208, asdescribed above with respect to FIG. 14 can provide a flexibleconductive pathway between the signal ear post 2206 and the conductiveportion 2212 of SMA connector 2210.

In one or more examples, an elastomeric conductor may not be requiredand the signal ear post 2206 may be directly mated to the conductiveportion 2212 of SMA connector 2210. However, as descried above, withoutthe elastomeric connector the connection between the signal ear post2206 and the conductive portion 2212 of SMA connector 2210 may bevulnerable to mechanical failure during operation of the phased arrayand any associated vibration environment incurred by the phased arrayduring operation.

While the example of FIG. 22 illustrates a connection between an SMAconnector and the signal ear post 2206, the disclosure should not beconstrued as limiting and the same configuration of FIG. 22 can be usedto connect the signal ear post 2206 with another type of connection suchas with a PCB connection.

Furthermore, in one or more examples hollow cylinders of non-conductivematerial can be inserted into the airgap 2204 to provide precisecentering and structural support for the signal ear post 2206 of thesignal ear. In one or more examples, the non-conductive material can becomposed of Teflon®. The addition of a non-conductive material can helpto reduce the risk of mechanical failure of the connection between thesignal ear post 2206 and the conductive portion 2212 by dampening anyvibration that may occur at the base plate 2202.

As briefly discussed above, configuring a unit cell of a phased arraysuch that the components can be built from a single part, allows foradditive manufacturing techniques to be applied when building the phasedarray. Additive manufacturing can involve joining and adding materialtogether to generate a single component. With respect to the all-metalphased array embodiments described above, the fact that the signal ear,ground ear, and base plate can be built from a single metal part, allowsthe array to be manufactured using additive manufacturing techniques.

In one or more examples, the all-metal phased array antenna can bemanufactured using an additive manufacturing process known as directmetal laser sintering. In a direct laser sintering process, a high-powerdensity laser is steered through a computer generated path, fusingtogether metal powder to create the phased array parts. In one moreexamples, the metal powder can comprise Al Si₁₀Mg aluminum alloy powder.When the laser comes into contact with the powder, the portion thatcomes into contact fuses together to form a metal surface. A computercan steer the laser in a very precise path so as to create all thenecessary components for a phased array as a single continuous part.

FIG. 23 illustrates an exemplary method for manufacturing an all-metalphased array according to examples of the disclosure. The method 2300can begin at step 2302 in which a metallic alloy powder can be depositedinto a container or deposited on a surface so as to be accessible by abeam of a high power laser. In one or more examples, the laser can be acarbon dioxide laser that can generate a beam with sufficient power soas to fuse together the metallic power upon contact, thereby generatingthree dimensional shapes.

Once the metallic powder has been deposited, the process can move tostep S2304 wherein the laser can be guided in a particular path throughthe metallic powder to generate the ground ear described above withrespect to the all-metal design. At step 2306 the laser can be guided bya computer to generate the base plate, and at step S2308, the laser canfurther generate an airgap within the base plate so as to accommodateone of the posts from the signal ear as described above. At step S2310,the laser can also be guided to generate the signal ear.

While the above example employs laser sintering, the disclosure shouldnot be seen as limiting, and the phased array described above can bemanufactured using other additive manufacturing techniques such asbinder jetting, VAT photopolymerization, stereolithogrpahy, power bedfusion, material jetting, sheet lamination, material extrusion, directedenergy deposition, or any combination of the above mentioned additivemanufacturing techniques.

The foregoing description, for purpose of explanation, has beendescribed with reference to specific embodiments. However, theillustrative discussions above are not intended to be exhaustive or tolimit the invention to the precise forms disclosed. Many modificationsand variations are possible in view of the above teachings. Theembodiments were chosen and described in order to best explain theprinciples of the techniques and their practical applications. Othersskilled in the art are thereby enabled to best utilize the techniquesand various embodiments with various modifications as are suited to theparticular use contemplated.

Although the disclosure and examples have been fully described withreference to the accompanying figures, it is to be noted that variouschanges and modifications will become apparent to those skilled in theart. Such changes and modifications are to be understood as beingincluded within the scope of the disclosure and examples as defined bythe claims.

What is claimed is:
 1. A phased array antenna comprising: a plurality ofunit cells, wherein each unit cell comprises: a base plate, wherein thebase plate includes an airgap disposed within the base plate, andwherein the base plate is configured to provide a path to ground ; asignal ear, wherein the signal ear includes a first post that isdirectly integrated into the base plate, and wherein the signal earincludes a second post that is disposed within the airgap of the baseplate; a ground ear, wherein the ground ear includes a post that isdirectly integrated into the base plate; and wherein the base plate, thesignal ear, and the ground ear form a single continuous part.
 2. Thephased array antenna of claim 1, wherein the base plate, the signal ear,and the ground ear are formed using an additive manufacturing process.3. The phased array antenna of claim 2, wherein the additivemanufacturing process includes stereolithography.
 4. The phased arrayantenna of claim 2, wherein the additive manufacturing process includesVat polymerization.
 5. The phased array antenna of claim 1, wherein thesecond post of the signal ear is connected to a flexible conductor on afirst side of the flexible conductor.
 6. The phased array antenna ofclaim 5, wherein the flexible conductor is connected to a rigidconductor on a second side of the flexible conductor.
 7. The phasedarray antenna of claim 6, wherein the signal ear, the flexibleconductor, and the rigid conductor are configured to create anelectrical path between the signal ear and the rigid connector.
 8. Thephased array antenna of claim 7, wherein the flexible conductor is anelastomeric conductor.
 9. The phased array antenna of claim 8, whereinthe elastomeric conductor is a Fujipoly Zebra connector.
 10. The phasedarray antenna of claim 8, wherein the elastomeric conductor is a fuzzbutton connector.
 11. The phased array antenna of claim 1, wherein thephased array comprises: a first grounded pillar projecting from the baseplate, wherein the first grounded pillar is directly integrated into thebase plate, and wherein the first grounded pillar is disposed adjacentto the signal ear.
 12. The phased array antenna of claim 11, wherein thephased array comprises: a second grounded pillar projecting from thebase plate, wherein the second grounded pillar is directly integratedinto the base plate, and wherein the second grounded pillar is disposedadjacent to the ground ear.
 13. A method for manufacturing a phasedarray antenna, the method comprising: continuing to add material in anadditive manner to form a base plate, wherein the base plate includes anairgap disposed within the base plate, and wherein the base plate isconfigured to provide a path to ground; continuing to add material in anadditive manner to form a signal ear, wherein the signal ear includes afirst post that is directly integrated into the base plate, and whereinthe signal ear includes a second post that is disposed within the airgapof the base plate; continuing to add material in an additive manner toform a ground ear, wherein the ground ear includes a first post that isdirectly integrated into the base plate; and wherein the base plate, thesignal ear, and the ground ear form a single continuous part.
 14. Themethod of claim 13, wherein adding material in an additive mannerincludes employing a stereolithography process.
 15. The method of claim13, wherein adding material in an additive manner includes employing aVAT polymerization process.
 16. The method of claim 13, the methodcomprising connecting the second post of the signal ear to a flexibleconductor on a first side of the flexible conductor.
 17. The method ofclaim 16, the method comprising connecting the flexible conductor to arigid conductor on a second side of the flexible conductor.
 18. Themethod of claim 17, wherein the signal ear, the flexible conductor, andthe rigid conductor are configured to create an electrical path betweenthe signal ear and the rigid connector.
 19. The method of claim 18,wherein the flexible conductor is an elastomeric conductor.
 20. Themethod of claim 19, wherein the elastomeric conductor is a FujipolyZebra connector.
 21. The method of claim 13, the method comprising:continuing to add material in an additive manner to form a firstgrounded pillar projecting from the base plate, wherein the firstgrounded pillar is directly integrated into the base plate, and whereinthe first grounded pillar is disposed adjacent to the signal ear. 22.The method of claim 21, the method comprising: continuing to addmaterial in an additive manner to form a second grounded pillarprojecting from the base plate, wherein the second grounded pillar isdirectly integrated into the base plate, and wherein the second groundedpillar is disposed adjacent to the ground ear.
 23. The method of claim13, the method comprising inserting a non-conductive material into theairgap, wherein the non-conductive material is disposed between an outeredge of the airgap and the second post of the signal ear.